Hi KaraC: Just think about the titles of the books: Sorcerer's Stone, Chamber of Secrets, Prisoner of Askaban, Goblet of Fire, Order of the Phoenix. Books 1, 2, 4 are spells that Harry had to break. Book 3 was about a man who Harry believed was his enemy who turned out to be his friend. Book 5 was about the order dedicated to good magic.

So I wonder if book 6 will be about a man who Harry thinks is his friend and turns out to be his enemy--the opposite of Book 3. I admit, this theory could be totally lame but with nothing else to go on, why not?